This invention relates to igniters and to methods of manufacture of igniters.
The invention is more particularly concerned with igniters having a tungsten tip.
Igniters used in high temperature applications, such as in gas-turbine engines, are prone to excessive electrical erosion. In order to keep this erosion to a minimum, the tips of such igniters are generally made of tungsten. This helps to prolong the life of the igniter to a certain extent, but the igniter tip can still oxidize and erode away rapidly at high temperatures, leading to a loss in reliability and to a high cost of replacement. Oxidation of the electrodes can lead to a dimensional increase in size of the electrode with consequent fracture of, for example, a semiconductor discharge pellet, or insulation between the electrodes.